Motion picture apparatus



April 1939- R. E. DE KAY 2,154,809

MOT ION PICTURE APPARATUS Filed July 13, 1936 4 Sheets-Sheet? gg N,fi'wemzfor:

ROBERT 5. DE KAY Am /rem ATTORNEY A r-H18 1939-. DEW 2,15 ,8 9

MOTION PICTURE APPARATUS Filed July 13,1936 4 Shets-Sheet 4 INVEAYTDR W76 Y flu-z 8%, 1/8 I AZTORNL'Y UNITED STATES PATENT OFFICE MOTIONPICTURE anraia'rus manexmmmeacam. I Application July 1:, 1930, SerialNo. 90.305

'4Clalml.

This invention relates to motion picture projectors and cameras of thattype in which the film I does not move intermittently but passes betweenthe source of light and the aperture plate at a constant and uniformspeed. It makes possible the use of film either with or without sprocketholes and, which is even more important, it makes practicable for thefirst time the use of such thin and fragile materials as Cellophane inplace of the usual celluoid films. The advantages, such as cheapness,cleanness, remarkable transparency and non-infiammability of Cellophaneover celluloid, are well known to those familiar with the art; but itsuse has hitherto been impracticable because such thin material, cannotstand the wear, tear and jerking of the intermittent machines.

Many other advantages of a projector or camera giving a steady anduniform movement to the film may be suggested. First, such a machinemay, by using direct gearing and a positive motion cam, be madesubstantially noiseless. Second, it allows the picture and the soundtrack to be taken side by side; which makes -it possible to repairbreaks at any point of the film without damage to the synchronization ofpicture .and sound. Third, this type of projector may be manufacturedmore cheaply than intermittent machines, and will retain its emciencyfor much longer periods. Fourth, it may be run at any desired speedwithout damage to the film,'a feature of great significance in colorphotography and projection. Fifth, use of such a' machine greatlyreduces the fire hazard, since the film is 'always in motion and isunder less strain; the

tendency to break thus being much less. And there are other advantagesof somewhat less importance; so it will readily be seen that apracticable uniform picture apparatus is a muchneeded advice.

It is the chief object of this invention to pro-' vide a. machineembodying in practicable" form the above enumerated advantages.

Attempts have been made to provide the art with such a machine but, tothe best of my knowledge, none has been a practicable success. g'I'hiswas due either to an incomplete understanding of the function of theoscillating mirror, or, more probably; to inadequate means forprovidingsuch oscillation. The mirror, of course, must move at a speednecessary to keep the angles of incidence and of reflection alwaysequal, in order to provide thenecessary light ray correction. Buttheprior devices have the mirror arm. acting directly from the actuatingcam with a swing motion. thus I giving to the mirror not a true uniformmotion,

but a harmonic one, which destroys its usefulness by projectingunsteady, fuzzy pictures.

It is another object of the invention to provide an apparatus for givingthe proper motion to the 5 oscillating mirror. so that clearpictures-will obtain. a In a continuous motion picture projector orcamera the aperture through which the film is.

projector equipped with the invention, some of the more immaterial partsbeing broken away;

Fig. 2 is an end elevation as seen from the left in Fig. 1; certainparts being broken away;

Fig. 3 is a view similar to Fig. 2, but on'a larger scale and with anobscuring member'omitted; 5

Fig. 4 is a view similar to Fig. l, but on a larger scale and showingonly the essential mechanism;

Fig. 5 is a sectional view, on a larger scale, taken on line 5-8 of Fig.2;

Fig. 8 is an elevation, on a larger scale, of the side opposite thatshown in Fig. 1, its chief purpose being to illustratethe drivingmechanism, details in the background being omitted for purposes ofclarity;

Fig. 7 is an elevation, on a somewhat smaller scale, of the shutter;

Fig. 8 is a side elevation of a modification of the shutter of Fig. "I;

Fig. 9 is an enlarged view of a detail of the drive mechanism;

Fig. 10 is an enlarged view of the apparatus for, oscillating themirror;

Fig. 11 is a sectional view, somewhat enlarged, taken on line li-ll ofFig. 10;

Fig. 12 is a view of a modification of the apparatus shown in Fig. 10;

Fig. 13 is a sectional view, on a larger scale, taken on line Il-ll ofFig. 4. and

Fig. 14 is an enlarged view of the apparatus used for adjusting theaperture plate.

In brief recapitulation, the invention comprises a continuous motionprojector or camera, an oscillating mirror for correcting the lightrays,

desired rays, and driving means for these elements.

Referring more particularly to the drawings, i8 is a suitable source oflight which may be mounted on rods II for adjustment relative to themotion picture projector.- A plate or table [2, bearing the projector,is supported by legs l3, and to the plate 12 is rigidly secured an arml4 at the upper and lower ends of which are respectively secured arotatable delivering reel I5, and a'rotatable receiving reel 16. Thefilm i1 passes from reel i5, thmugh the projector, and is wound uponreel IS. The course of the film is shown in Figs. 1, 4 and 5,particularly in Fig. 5, to which reference is now made. From reel l5 thefilm first passes over a driven sprocket l8, to which it is held tightlyby a roller l9. Roller [9 (Fig. 4) is carried by an arm 28, which ispivoted at 2| and is pressed against the film and sprocket l8 by aspring member 22, operating on the arm. Rigidly secured to table I2 isan upright plate 23 to which the aperture plate and its associatedmechanism (to be described) is attached. From sprocket I8 the filmextends in a loose curve indicated at 24 to and over a roller 25 pivotedto a support which is rigidly attached to plate 23. The film is curved,as at 24, to provide a slack, thus to prevent any drag or jerking whichmight injure it. From roller 25 the film is guided by curved elements 26between the aperture plate 21 and a swinging holder 28, to be describedlater and best shown in Fig. 3. Other elements 29, carried by the holder28, curve oppositely to the elements 28 and guide the film to a tensionroller 30, which is joumaled to an arm 3!; said arm 3| being pivoted toan extension 3P of the aperture plate 21 and being adjusted by a setscrew operating in spaced depressions 32 in an extension 33 of the saidplate. A bar 34 having a curved inner surface guides the film downwardlyto a second driven sprocket 35, against which the film is held by aspringpressed roller 36. After the film has passed about and over theroller 38 it passes to a fixed roller 31 and is bent thereby to passthrough a slot 38 in the table 12, and so to a third driven sprocket 39,from whence it extends in a loose curve to reel IS. The film is held tosprocket 39 by a spring-pressed roller 39.

The swinging holder 28 is in the shape of an open rectangular framecomposed of upright bars 40 connected by horizontal bars 4| which extendat one side beyond the holder and are apertured to receive a rod 42. Itwill be noted that curved elements 28 and 29 are the bent ends of'bars48. Brackets 43 project from the holder 28 and are also apertured toreceive the rod 42; so it will be seen that the holder 28 is similar toa hinged door with rod 42 serving as the pivot pin. The holder pressesthe film against the aperture plate, such pressure being exerted by aspring 44 connecting the holder to the upright plate 23.

The aperture plate 21 is removable, and is also adjustable bothvertically and horizontally, by means of mechanism best seen in Figs. 5and 14. These features are desirable because the removal of the plateallows for easy cleaning and repairing, and because the adjustmentpermits exact alignment of the aperture with the mirror. A disc 45 isremovably secured, as by a threaded bolt 46, to plate 23. The apertureplate 21 and,

consequently,-holder 28, are supported by a transverse bar 41, to whichis rigidly secured a pin 48 which is inserted downwardly in a bore 49 ofdisc 45. Bolt 46 impinges upon pin 48, as seen in Fig. 5 and it will benoted that by loosening bolt 48 the aperture plate may be raised orlowered as pin 48 slides in bore 49, and can be held in the desiredposition when the bolt is again tightened. Pivotally secured to disc 45is a member 58, which is preferably a short cylinder though the shape ofthis element is immaterial. A bracket or extension 5|, rigidly securedto plate 23, is apertured to receive a screw-threaded rod 52, capped byany suitable means 53 for turning, rod 52 being screwed through acentral threaded bore (not shown) in the member 58. As will be seen, anyturning of rod 52 will vary the distance between bracket 51 and member58, which causes a slight turning and shifting of the disc 45 and pin48, with the result that the aperture plate is tilted in a verticalplane.

Turning now to the driving mechanism, a motor 54 is suitably secured tothe table I2. From its pulley 55 a cable or belt 58 connects with apulley 51 joumaled on a shaft 58 which is secured to a plate 58extending upwardly from table l2. A second pulley 88 is rigidly securedto pulley 51 and, from pulley 68, a cable or belt 8| connects with apulley 82 on a shaft 83. Turning with shaft 83 is a large pinion 84adapted to drive a chain 65 which also acts to drive a second largesprocket pinion 88, thus to turn the shaft 81 to which pinion 86 issecured. As will be seen in Fig. 3, shaft 83 drives the sprocket 35, andshaft 81 drives sprocket l8, both sprockets being of equal size andnecessarily turning at the same speed and in the same direction due tothe positive drive of chain 65. Upon the shaft 63 is yet another pulley88 (Fig. 3) from which the reel I8 is driven by a. cable or belt 69(Fig. 6). Also upon the shaft 83 is a large gear 18 intermeshing at itslower face with a small gear 1 I. Gear 1| in turn intermeshes withanother large gear 12 which drives a shaft 13 and thereby the sprocket38. Gears 18, 1| and 12 have the ratio necessary to drive sprocket 39 atthe same speed as sprockets l8 and 35, so it will be seen that upon theactuation of motor 54 the film i1 is simultaneously driven at threedifferent points.

Intermeshing at its upper surface with gear 10 is a small gear 1.4 (seenbest in Fig. 9) which is adapted to rotate a shaft 15, for a purposepresently to be disclosed. Adjacent gear 14 upon shaft 15 is a worm 18meshing with a second worm 11 upon a shaft 18 extending at right angleswith shaft 15 and suitably joumaled at points 19 and 88 (Fig. 6).Rotating with shaft 18 is a mitre gear 8| (Fig. 3). The shaft 18 passesthrough the upper part of a bar 82, the lower end of which is removablysecured to a stub shaft 83 extending from plate 23. A second mitre gear84 meshes with gear 8|, and is secured to a shaft 85 suitably joumaledupon the bar 82. A third mitre gear 88, upon shaft 85, meshes with afourth mitre gear 81, which drives a shaft 88. It will be observed thatthe four mitre gears transfer the rotation of shaft 18 to shaft 88 andtheir ratio is such that the shafts rotate at the same speed. Further,when the bar 82 is disconnected from the stub-shaft 83, it can be swungabout shaft 18 and, inso doing, it will carry the shaft 85 and the mitregears 84 and 88 with it.

Rotating with the shaft 88 is a shutter 88 having an opening in theshape of a broken spiral 80, the purpose of which will be discussedlater in another connection.

The upright plate 28 has two horizontal slotlike openings. The lower ofthese, 9| permits passage of the film and allows room for the rotationof sprocket 36, as seen in Fig. 5. The

upper opening, shown at 92, permits e of light from the aperture of theaperture plate to the reflecting apparatus. Secured to plate 23 is abracket 93 having a transverse strengthening member 94 which isapproximately at the upper edge of opening 9i. Rigidly secured at theupper edge of bracket 93 is an arm 96 which extends upwardly at an angleand supports the oscillating mirror 96.

Below mirror 96 and approximately parallel thereto is a second mirror 91rigidly held in place by set screws 99 which press the mirror againsttransverse rods 99 secured in end members I00. It will be understoodthat, by changes adjustable by pushing or pulling it between and behindthe said rollers. This permits fore and aft adjustment of the'reflectingmirror 91 with respect to the oscillating mirror 96 and the lenses I04,which are held in a cylindrical container I06 secured to a bar I06 andfurther supported by an encircling band I01. A rod I03 extends throughthe end of bar I06 and is removably and adjustably held therein by a setscrew I09. Rod I09 is preferably integral with a short block IIO whichhas a bore at right angles to the rod I03, the bore being adapted tocontain loosely a pin III and to slide upon such pin. The pin is setsolidly in upright I4. A second set screw I I2 holds the block H in thedesired position. It will be observed that, like the reflecting mirror,the lenses are also adjustable longitudinally.

Referring again to Fig. 9, and to Fig. 10, shaft 16, receiving itsactuation through gears 10 and 14, is journaled in plate 39 and bracket93, and

beyond bracket 93 it carries a cam II3 which is rigidly secured to, oris integral with, a strengthening disc II4. Cam H3 is recessed at II toprovide a bearing surface for a circular extension II6 of a supportingmember or arm II1, to be described. Shaft 16 extends through extensionII 6 and arm H1 and is free to turn in the bores therein, and may beterminated with a fly wheel H3. Such a flywheel has a tendency to steadythe movement of the cam and, though it is not shown in Figs 1 to 6, itis understood that its use there is contemplated, if desired.

Referring now to Figs. and 11, the arm H1 and its associated mechanismwill be described. At suitable distances on arm III are bearings II9,secured to the arm as by bolts I20, and having a central bore designatedto permit easy longitudinal sliding of a rod I2I, the bore beinglengthened by the insertion of. bushings I22. At one end the rod I2I isprovided with a screwthreaded pin I23 having a head I24 adapted to rideupon the cam II3. At its other end, beyond an additional strengtheningbearing I26, the rod I2I carries a removable cap I26 to limit itsmovement. Slidably mounted upon rod I2I, between bearings H9, is a discI21 upon which, and preferably integral therewith, is a hollow cylinderI23 having two broad slots I29 extending from its upper end almost tothe disc I21. Set within the hollow cylinder I23, in such manner that itconnects pin I33 with any suitable attachment on upright plate 23, asshown in Figs. 4 and 5, and, as'will later be discussed in more detail,provides the necessary tension to keep the head I24 of pin I23 pressingconstantly against cam II3 Referring particularly to Fig. 4, theoscillating mirror 96 is held between end members I35" (similar tomembers I00 of the reflecting mirror). Rigidly.v secured to end memberI36 through a pin I36 is a small disc-shaped element I36 having a borewithin which pin I33 is immovably held. Arm H1 is, of course, supportedat its lowerend by its bearing on shaft but since the pin I33 "fitsloosely in cylinder I30, an additional support is necessary. A rod I31is held to the arm II1 through a block member having a tightening memberI39 adapted to fit screwthreads in the arm. A second block member" ordisc I39 is removablysecured to a rod or pipe I40 (Fig. 5) which isfastened firmly to the back plate 69. Such fastening is not shown, butmay be of any suitable kind. A second block member or disc MI isadjustably secured to disc I39; and both discs have a bore to allow rodI31 to slide when not held by set screw I42. Thus when the pin I33 hasbeen inserted in bore I3I of cylinder I30, the arm H1 is raised until inits proper position, carrying with it rod I31, and then set screw I42 isscrewed flrmly upon the rod, holding the rod and consequently arm H1 inthe position selected.

It has been found that in order to give perfect results the pin I33 mustbe at right angles to rod I2I. That is, the pin and rod will be at righta'ngles at the middle of the rods endwise 96, which in turn varies thespeed and amount of the mirrors oscillation. The adjustment synchronizesthe motion of the mirror with the motion of the film. Inasmuch as thefilm has a tendency to shrink, itwill be seen how essential such anadjustment becomes.

The means for oscillating the mirror 96 functions as follows: Driven byshaft 16, the cam II3 turns about the extension II6 on the'arm H1 and,through the head I24 of pin I23, moves the rod I2I endwise carrying withit the disc I21. Pin I33, being held rigidly to the mirror structure, isswung by cylinderI30; and cylinder I30, being loosely contained inthehollow cylinder I23, as the pin is rocked, rotates; such rotationbeing madepossible by the slots I29 in the hollow cylinder I30. The pin,then, moves in a slight arc and, since it is immovably connected to themirror structure, the mirror moves in a similar arc. As the thinnerportion of the cam H3 comes into contact with the head I24, the

spring I34 pulls pin I33. backwards and so moves the rod I2I; both thepin and the mirror re. versing the short are previously covered. It willbe remembered that cam H3 is driven positively pass the aperture plate.Any device for cutting from the mechanism which drives the film, whichassures that the mirror moves with each picture on the film as thelatter progresses past the aperture plate.

In Fig. 12 a variation is shown of the mechanism just described foroscillating the mirror. In some particulars this device is the preferredform, though it accomplishes the same results. Where the elements haveremained unchanged, the same reference numerals will be used. A plateI45 replaces arm Ill, and iournaled therein, is the shaft I5. Shaft 15carries a worm gear I which meshes with a second worm gear I turningwith a hollowsshaft I45. A grease box I" is fastened suitably to plateIll, and within the box two cams are adapted to cooperate. A rod I55 isextended through the hollow shaft I55, is journaled at one end of thegrease box, at I45, and in a bracket I55, and ends within a cylinderI5I. Cylinder 'I5I contains a coiled spring I52 and is provided with ascrew-threaded device I55 for adjusting the tension of the spring, whichis held between device I55 and the flanged end I55 of rod I45. Mountedupon rod I55 is the disc I21 holding cylinder I55 which receives the pinI55, as in the apparatus shown in Fig. 10. 8ecured' to the shaft I55within box I" is a cam I55 having a face surface which slopes to anabrupt drop I55. Opposing the cam I55, and secured to rod I55, is asecond cam I51 having a surface which slopes to an abrupt drop I55. Thespring I52, it will be observed, keeps cam I51 pressed against cam I55.In operation, with the turning of worm I45 the cam I55 turns against camI51, their sloping surfacs forcing rod I55 back against spring I52 untilthe drops I55 and I55 coincide, when the pressure of the cams againstthe spring suddenly ceases and the springas suddenly snaps rod I45 inthe opposite direction until the cams again connect. The movement thusgiven pin I55, and consequently the oscillating mirror, is substantiallythe same as that given'by the apparatus of Fig. 8; but the change makespossible a more abrupt return of the rod and mirror than could beobtained with use of cam H5.

Another important feature of the invention is the shutter, shown at 59in Figs. 2 and I, and a modification of which is shown in Fig. 8. Thenecessity for its use may readily be made apparent by a comparisonbetween continuous motion projectors and those operating intermittently.In the intermittent machine, each picture on the film is shownmomentarily, then is jerked out of sight to make room for the nextpicture, and so on. This jerking, parenthetically,-is the chief obstacleto the use of cellophane films, which are too delicate for suchtreatment. In the intermittent machine the aperture is substantially thesize of the individual picture on the film, but in a continuous machinethe aperture must be much longer to permit the picture to be followeddown, and this, but for the means now to be de:- scribed, would allowundesirable light rays to out these extra rays must, of course, traveluniformly down with the film and return instantly for the next exposure.To obtain this result I have provided a circular rotatable shutter andhave placed it between the light source and the film. This location isimportantsince it not only prevents undesirable light rays from reachingthe film, but also cuts down considerably the amount of heat from thelight source which otherwise would fall constantly on the film andmechanism.

TheshuttershowninFigs.2and'lisadrcular sheet of any suitable material(cardboard and other fibrous material being quite satisfactory) throughwhich a spiral slot 55 has been cut. The pitch of the slot is the lengthof a single picture on the film. If it be assumed that the shutter ofFig. '7 is turning in a'clockwbe direction, the picture will firstappear (for example) at point I55 and will be exposed until the shutterhas turned far mough to bring point I55 to where a point I55 isindicated.

At this point begins a flicker blade "I, interrupting the slot. ,Atpoint I52 the slot is continued and the light again shines through theshutter, the picture showing until the point I55 is reached, when thelight is cut oil. by an interruptionl. Aswillbeseeninl'lg.7,theslot hastraveled down with the picture a distance equal to the length of thepicture. Then the next picture on the film is seen at point I55. 'Iherewill, during the revolution of the shutter, be two interruptions whenthe light is cut oil momentarily. Interruption I54 is to allow the slotto coincide with the next picture as it first beginsto pass theaperture. The flicker blade "I has two purposes. First, it serves tostrengthen the shutter by forming a second connection between its centerportion and the rim beyond the slot. Second, it serves, in a manner, torest the eye. Were the picture to be illuminated con tinuously frompoint I 55 to point I55 of the slot, the shift to the second picturewould be noticeable and objectionable. but when this is balanced by asecond flicker (passage of interruption I5I across the aperture),neither blind spot is noticeable.

There are two objections to shutter 55, though neither is serious. Onsmall projectors where space is limited, and oncamaras, a large fiatshutter cannot be used. But a flat shutter must be large so that thecurve of the spiral will not be so small that it will show appreciablyin the picture. To avoid these difiiculties I have designed the shuttershown in Fig. 8. This shutter is in the form of a truncated cone I55,the slot I55 being cut in the sides, and having an interruption I51 anda fiicker blade I65. It will be understood that by this construction thesame results are obtained as would be were the cone a cylinder with thelight source in its centerthat is, there will be no curved edge thrownon the film, but a straight line, slightly at an angle to the horizon.This shutter can be made quite small in comparison with shutter 55.

The operation of the machine as a whole will need but brief comment,since the elements not described in detail are an old story to thoufamiliar with the art. Thou features which form a part of the inventioncomprise the shutter, the

positive drives simultaneouly moving the film,

"tinuously moving film, means for producing a stationary image from themoving film image, such means comprising a mirror adapted foroscillation, and means for oscillating the mirror, such latter meanscomprising a rod adapted for endwise movement, an arcuate surfacedbearing member attached to the rod, a pin attached to the mirror andadapted to be actuated, an arcuate Journal in the bearing memberconnected with the pin, a cam for-moving the rod, and means for drivingthe cam.

2. Apparatus as described in claim 1 including means to mount thereciprocating rod at substantially right angles to the pin.

3. In a motion picture machine having a continuously moving film, anaperture plate containing an aperture, means for adjusting the apertureplate vertically, and means for adjusting the aperture .platehorizontally, in combination with means for producing a stationary imagefrom the moving film image, such means comprising a mirror adapted foroscillation and means for oscillating the mirror, such latter meanscomprising a rod adapted for endwise movement, an arcuate surfacedbearing member attached to the rod, a pin'attached to the mirror andadapted to be actuated, an arcuate journal in the bearing memberconnected with the pin, a cam for moving the rod, and means for drivingthe cam.

4. Apparatus as described in claim 3, in combination with means foradjusting the position of the rod with respect to the mirror, for thepurpose described, and means to mount the reciprocating rod atsubstantially'right angles to the pin.

ROBERT E. DE KAY.

